On edit trigger that inserts timestamp dependant on checkbox value - checkbox

Question

I'm trying to develop an inventory sheet for my company I work for in Google Sheets. In the system, I'm wanting if a checkbox in Column C is ticked it will display the "checked out time" in Column D, and if unticked will display the "checked in time" in Column E. However, I'm wanting when the item is checked in, the checked out date/ time cell turns back to blank.
I've used this custom function script to create a TIMESTAMP function that works, but every time the spreadsheet is reopened is recalculates all the date to the current date/time. Any way of making it non-volatile?
function timestamp() {
return Date();
}
Would I need a onedit trigger that could do what I described above?
WARNING: I'm not scripting savvy at all.I've been scouring the forums for the past week and can't get anything that works. Any help would be greatly appreciated :D
Link: https://docs.google.com/spreadsheets/d/1Oj6eustjvk9opXFNR2jHa0uMjPnKVXsvwOxFjb1t7-8/edit?usp=sharing

Answer 1

Here is the code i used for exact same scenario.
probably not the most efficient code but it works,
you can adjust it to your needs
var timezone = "GMT-0400";
var timestamp_format = "MM/dd/yyyy HH:00"; // Timestamp Format.
function onEdit() {
var s = SpreadsheetApp.getActiveSheet();
if( s.getName() == "Sheet1" ) { //checks that we're on the correct sheet
var r = s.getActiveCell(); //watches edited cell
if( r.getColumn() == 2 ) { //checks if edit is in column 2,
var nextCell = r.offset(0, 2);
if( r.getValue() === false)
nextCell.setValue(new Date()).setNumberFormat("dd-MM-yyyy HH:mm:ss");
if( r.getColumn() == 2 ) { //checks the column
var nextCell = r.offset(0, 1);
if( r.getValue() === true)
nextCell.setValue(new Date()).setNumberFormat("MM-dd-yyyy hh:mm:ss");
if( r.getValue() === false)
Browser.msgBox("Data refreshed.");
};
};
}
}